Characterization of a monoclonal antibody enhancing porcine natural killer cell activity (PNK-E).
A monoclonal antibody, termed PNK-E, that functionally enhances porcine natural killer (NK) cell activity but not antibody-dependent cellular cytotoxicity (ADCC) is investigated in this report. When PNK-E and K562 target cells were simultaneously added to effector cells, killing of target cells could be detected as early as 30 min, and a dramatic enhancement of killing activity was observed in short term 51Cr-release assays. When a panel of five NK-sensitive targets were tested, PNK-E enhanced the killing of K562, MOLT-4, and U937 cells, but not the killing of CEM and YAC-1. F(ab)'2 fragments of PNK-E did not enhance NK activity, indicating a requirement for the Fc portion of PNK-E to elicit enhancement of NK. Immunofluorescence analysis shows that PNK-E antigen is expressed on approximately 15% of peripheral blood lymphocytes with a relatively dull fluorescence staining pattern. PNK-E-positive sorted cells were enriched for large granular lymphocytes (LGL) and contained all detectable NK activity as compared to the PNK-E-negative sorted cells. When analyzed by polyacrylamide gel electrophoresis, PNK-E antibody immunoprecipitated a protein from 125I-labeled peripheral blood lymphocyte (PBL) cell lysates that resolved as a single band of approximately 205 kDa under nonreducing conditions and as two bands of approximately 50 kDa and 47 kDa under reducing conditions. The present data demonstrate a functional association between PNK-E antigen and NK cell activation.
Johnson
B D
BD
Department of Microbiology and Immunology, University of Health Sciences, North Chicago, Illinois.
Kim
Y B
YB
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000920:Antibody-Dependent Cell Cytotoxicity; D000954:Antigens, Surface / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D007113:Immunity, Innate; D007141:Immunoglobulin Fc Fragments / Q000276:immunology; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology*; D013552:Swine
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007141:Immunoglobulin Fc Fragments